QTR-Quadtone RIP

I posted this on the piezo forum but I think it is more appropriate for
here. I have been through the archives and I am starting to understand the
icc usage but would like a little more clarification.
I using a pc/k7 inks/2200/hpr308

Well I went through the motions
and printed a 21 step wedge using qtr/ the k7 curve/ and output in
gamma 2.2 as suggested. I then took the readings (albeit with a
scanner) and put those numbers in a text file and dragged it into the
create icc.
I am using a PC so I went back to my image in gamma 2.2 and converted
it to this new profile and printed again. Everything seemed a bit
lighter than before. I will have someone read the wedge with a spectro
so I can get better results but I'd like to know something about this
ICC stuff.....what's it do? :)
If I made these curves myself with this printer/paper/and ink combo in
gamma 2.2(instead of the supplied curves with QTR), I wouldn't need to do
this right? Is this kind of minor
curve adjustment for variations in printer/paper/ink than when the
curves were made?
If so, is this what people do if they made there own curves, everything
is great, but then (for example) they get a new batch of the same paper and
the
blacks are inking out. Instead of making a whole new curve you would
just make a new ICC???
I read in the archives this is much more than just a soft proofing
technique.  To me it seems to be another layer of linearization. So if
that's the case, how is it different than linearizing a curve??
For the supplied k7 curves I can't linearize so this is a great option, but
how about other curves that I might have created and already
linearized....why would I make an icc on top of that curve?

Thanks I really appreciate the help in understanding this.
Scott


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